Planetary Wave Characteristics in the Lower Atmosphere Over Xianghe (117.00°E, 39.77°N), China, Revealed by the Beijing MST Radar and MERRA Data

2017 ◽  
Vol 122 (18) ◽  
pp. 9745-9758 ◽  
Author(s):  
Chunming Huang ◽  
Shaodong Zhang ◽  
Gang Chen ◽  
Siyu Zhang ◽  
Kaiming Huang
Keyword(s):  
Planetary Wave ◽  
Lower Atmosphere ◽  
Wave Characteristics ◽  
Mst Radar

scholarly journals Tidal wind oscillations in the tropical lower atmosphere as observed by Indian MST Radar

2001 ◽  
Vol 19 (8) ◽  
pp. 991-999 ◽  
Author(s):  
M. N. Sasi ◽  
G. Ramkumar ◽  
V. Deepa
Keyword(s):  
Seasonal Variation ◽  
Solar Radiation ◽  
Meridional Wind ◽  
Radar Data ◽  
Short Wave ◽  
Tropical Meteorology ◽  
Lower Atmosphere ◽  
Radiation Absorption ◽  
Tidal Theory ◽  
Mst Radar

Abstract. Diurnal tidal components in horizontal winds measured by MST radar in the troposphere and lower stratosphere over a tropical station Gadanki (13.5° N, 79.2° E) are presented for the autumn equinox, winter, vernal equinox and summer seasons. For this purpose radar data obtained over many diurnal cycles from September 1995 to August 1996 are used. The results obtained show that although the seasonal variation of the diurnal tidal amplitudes in zonal and meridional winds is not strong, vertical phase propagation characteristics show significant seasonal variation. An attempt is made to simulate the diurnal tidal amplitudes and phases in the lower atmosphere over Gadanki using classical tidal theory by incorporating diurnal heat sources, namely, solar radiation absorption by water vapour, planetary boundary layer (PBL) heat flux, latent heat release in deep convective clouds and short wave solar radiation absorption by clouds. A comparison of the simulated amplitudes and phases with the observed ones shows that agreement between the two is quite good for the equinox seasons, especially the vertical structure of the phases of the meridional wind components.Key words. Meteorology and atmospheric dynamics (tropical meteorology; waves and tides)

scholarly journals Gravity wave characteristics in the lower atmosphere at south pole

1999 ◽  
Vol 104 (D6) ◽  
pp. 5963-5984 ◽  
Author(s):  
Matt Pfenninger ◽  
Alan Z. Liu ◽  
George C. Papen ◽  
Chester S. Gardner
Keyword(s):  
Gravity Wave ◽  
Lower Atmosphere ◽  
South Pole ◽  
Wave Characteristics

scholarly journals Features of 3–7-day planetary-wave-type oscillations in F-layer vertical drift and equatorial spread F observed over two low-latitude stations in China

2017 ◽  
Vol 35 (3) ◽  
pp. 763-776 ◽  
Author(s):  
Zhengping Zhu ◽  
Weihua Luo ◽  
Jiaping Lan ◽  
Shanshan Chang
Keyword(s):  
Planetary Wave ◽  
Rate Of Change ◽  
Lower Atmosphere ◽  
Main Role ◽  
Kelvin Wave ◽  
Low Latitude ◽  
Wave Type ◽  
Equatorial Spread F ◽  
Vertical Drift ◽  
Spread F

Abstract. Recent studies on the equatorial atmosphere–ionosphere coupling system have shown that planetary-wave-type oscillations, as an important seeding mechanism for equatorial spread F (ESF), play an important role in ESF irregularity development and its day-to-day variability in the equatorial latitudes. In this study, ionosonde virtual height and ESF measurements over Sanya (18.4° N, 109.6° E; 12.8° N dip latitude) and meteor radar neutral-wind measurements over Fuke (19.5° N, 109.1° E; 14° N dip latitude) during 2013 are used to investigate the features of planetary-wave-type oscillations in both the lower atmosphere and the ionosphere and their possible influences on ESF occurrence under the weak solar maximum year. The ∼ 3-day and ∼ 7-day planetary-wave-type oscillations have been observed in the neutral zonal winds and the time rate of change in F-layer virtual heights. According to the propagation characteristics, the 3-day and 7-day planetary-wave-type oscillations are basically recognized as ultrafast and fast Kelvin waves, respectively. With increasing heights, the 3-day wave oscillations are gradually amplified, while the 7-day wave oscillations are generally constant. By performing a cross-wavelet transform on the onsets of ESF and the vertical drifts of the F layer, we found that there are simultaneously occurring 7-day and 3-day common wave oscillations between them. The 7-day waves are mainly in the inversion phase, while the 3-day waves are mostly in an in-phase state, indicating that the 7-day waves may play a main role in ESF initiation. Approximate delays of 6 days for the 7-day waves and 5 days for the 3-day waves in their propagation upward from the lower atmosphere to the ionosphere are evaluated with wavelet power spectrum analysis. The estimated upward velocities from these time delays provide consistent evidence that the 7-day and 3-day waves propagate vertically upward with typical Kelvin wave characteristics. The results highlight the role of planetary-wave-type oscillations in the initiation and development of ESF in the Chinese low-latitude region.

scholarly journals Studies of the Polar Middle and Lower Atmosphere by an MST Radar on Svalbard.

1995 ◽  
Vol 47 (9) ◽  
pp. 929-942
Author(s):  
Jurgen Röttger ◽  
Toshitaka Tsuda
Keyword(s):  
Lower Atmosphere ◽  
Mst Radar

scholarly journals Planetary wave characteristics of gravity wave modulation from 30–130 km

2012 ◽  
Vol 10 ◽  
pp. 271-277 ◽  
Author(s):  
P. Hoffmann ◽  
Ch. Jacobi
Keyword(s):  
Planetary Wave ◽  
Middle Atmosphere ◽  
Model Simulation ◽  
Phase Speed ◽  
Circulation Model ◽  
Wave Characteristics ◽  
F Region ◽  
Zonal Wavenumber ◽  
Momentum Fluxes ◽  
High Phase

Abstract. Fast gravity waves (GW) have an important impact on the momentum transfer between the middle and upper atmosphere. Experiments with a circulation model indicate a penetration of high phase speed GW into the thermosphere as well as an indirect propagation of planetary waves by the modulation GW of momentum fluxes into the thermosphere. Planetary wave characteristics derived from middle atmosphere SABER temperatures, GW potential energy and ionospheric GPS-TEC data at midlatitudes reveal a possible correspondence of PW signatures in the middle atmosphere and ionosphere in winter around solar maximum (2002–2005). In the case of the westward propagating 16-day wave with zonal wavenumber 1 a possible connection could be found in data analysis (November–December 2003) and model simulation. Accordingly, GW with high phase speeds might play an essential role in the transfer of PW and other meteorological disturbances up to the ionospheric F-region.

scholarly journals Intensive radiosonde observations of the diurnal tide and planetary waves in the lower atmosphere over Yichang (111°18' E, 30°42' N), China

2009 ◽  
Vol 27 (3) ◽  
pp. 1079-1095 ◽  
Author(s):  
C. M. Huang ◽  
S. D. Zhang ◽  
F. Yi
Keyword(s):  
Lower Stratosphere ◽  
Wave Structure ◽  
Daily Basis ◽  
Planetary Waves ◽  
Lower Atmosphere ◽  
Diurnal Tide ◽  
Wave Characteristics ◽  
Nonmigrating Tides ◽  
Water Vapor Mixing Ratio ◽  
Different Characteristics

Abstract. The characteristics of diurnal tide and planetary waves (PWs) in the troposphere and lower stratosphere (TLS) over Yichang (111°18' E, 30°42' N) were studied by using the data from intensive radiosonde observations in August 2006 (summer month) and January 2007 (winter month) on an eight-times-daily basis. The radiosonde observations of the diurnal tide and PWs in the TLS in the mid-latitudes have seldom been reported. We find that there exists dominant diurnal oscillations in the TLS over Yichang. The observed diurnal tide consists of significant nonmigrating components, which may be owning to the local latent heat release. Since the nonmigrating tides are usually composed of high order modes with smaller vertical wavelengths, which are prone to dissipation in comparison with the low order modes, the observational tidal amplitudes decrease sharply at several heights. Some evident discrepancies between the observations and the GSWM-02 are found, which may result mainly from the inaccurate prediction of the nonmigrating tidal components by the GSWM-02. And, due to the evident seasonal differences of the water vapor mixing ratio disturbance and the tropospheric jet induced turbulence in winter, the diurnal tides in the summer and winter months have some different characteristics. Besides the diurnal tide, obvious quasi 7-day PW (QSDPW) and quasi 10-day PW (QTDPW) are also recognized from our observations in both the summer and winter months. The QSDPWs in the troposphere in both the summer and winter months show a standing wave structure, while the QTDPWs generally exhibit traveling wave characteristics. Spectral analyses reveal that some waves with periods around that of the diurnal tide are generated due to the interactions of the diurnal tide and PWs and the tidal amplitudes are modulated by the PWs, indicating the extensive coupling between the diurnal tide and PWs. Moreover, our observations manifest that the PWs can exert great impacts on the tropospheric jet in winter and the tropopause in both the summer and winter months.

scholarly journals Wave activity (planetary, tidal) throughout the middle atmosphere (20-100km) over the CUJO network: Satellite (TOMS) and Medium Frequency (MF) radar observations

2005 ◽  
Vol 23 (2) ◽  
pp. 305-323 ◽  
Author(s):  
A. H. Manson ◽  
C. E. Meek ◽  
T. Chshyolkova ◽  
S. K. Avery ◽  
D. Thorsen ◽  
...  
Keyword(s):  
Satellite Data ◽  
Total Ozone ◽  
Planetary Wave ◽  
Geometric Mean ◽  
Lower Thermosphere ◽  
Wave Activity ◽  
Lower Atmosphere ◽  
Medium Frequency ◽  
Longitudinal Sector ◽  
Contour Plots

Abstract. Planetary and tidal wave activity in the tropopause-lower stratosphere and mesosphere-lower thermosphere (MLT) is studied using combinations of ground-based (GB) and satellite instruments (2000-2002). The relatively new MFR (medium frequency radar) at Platteville (40° N, 105° W) has provided the opportunity to create an operational network of middle-latitude MFRs, stretching from 81° W-142° E, which provides winds and tides 70-100km. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43° N, 81° W), Platteville (40° N, 105° W), Saskatoon (52° N, 107° W), Wakkanai (45° N, 142° E) and Yamagawa (31° N, 131° E). It offers a significant 7000-km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14°) at two longitudes. Satellite data mainly involve the daily values of the total ozone column measured by the Earth Probe (EP) TOMS (Total Ozone Mapping Spectrometer) and provide a measure of tropopause-lower stratospheric planetary wave activity, as well as ozone variability. Climatologies of ozone and winds/tides involving frequency versus time (wavelet) contour plots for periods from 2-d to 30-d and the interval from mid 2000 to 2002, show that the changes with altitude, longitude and latitude are very significant and distinctive. Geometric-mean wavelets for the region of the 40° N MFRs demonstrate occasions during the autumn, winter and spring months when there are similarities in the spectral features of the lower atmosphere and at mesopause (85km) heights. Both direct planetary wave (PW) propagation into the MLT, nonlinear PW-tide interactions, and disturbances in MLT tides associated with fluctuations in the ozone forcing are considered to be possible coupling processes. The complex horizontal wave numbers of the longer period oscillations are provided in frequency contour plots for the TOMS satellite data to demonstrate the differences between lower atmospheric and MLT wave motions and their directions of propagation.

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